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Revalidation of the isobaric multiplet mass equation for the A=20 quintet

Journal Article · · Physical Review C, Nuclear Physics
 [1];  [1];  [1];  [2];  [2];  [1];  [1];  [3];  [3];  [1];  [2];  [2];  [1];  [2];  [1];  [4];  [1];  [5];  [6];  [3] more »;  [1] « less
  1. Michigan State Univ., East Lansing, MI (United States)
  2. Univ. of Notre Dame, IN (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Texas A & M Univ., College Station, TX (United States)
  6. Univ. of Surrey, Guildford (United Kingdom)
An unexpected breakdown of the isobaric multiplet mass equation in the A = 20, T = 2 quintet was recently reported, presenting a challenge to modern theories of nuclear structure. In the present work, the excitation energy of the lowest T = 2 state in Na-20 has been measured to be 6498.4 +/- 0.2stat ± 0.4syst keV by using the superallowed 0+ → 0+ beta decay of Mg-20 to access it and an array of high-purity germanium detectors to detect its gamma-ray deexcitation. This value differs by 27 keV (1.9 standard deviations) from the recommended value of 6525 ± 14 keV and is a factor of 28 more precise. The isobaric multiplet mass equation is shown to be revalidated when the new value is adopted.
Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE Office of Science (SC)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1261473
Journal Information:
Physical Review C, Nuclear Physics, Journal Name: Physical Review C, Nuclear Physics Journal Issue: 4 Vol. 92; ISSN 0556-2813; ISSN PRVCAN
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

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Cited By (2)

β -decay study of the T z = − 2 proton-rich nucleus Mg 20 journal January 2017
Observation of excited states in Mg 20 sheds light on nuclear forces and shell evolution journal February 2019

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